there are 2 types !!
1.stated-correctly express
2.implied-not stated with the paragraph.
It is the first sentence of a paragraph which is the topic sentence.
The purpose of a sentence is to express a complete thought. To be a complete thought, a sentence must contain a subject and a verb. (A verb is an action word, aka predicate.)
The topic sentence and sentences that expand upon it.
the first sentence of the paragraph is called the topic sentence which should describe most of the paragraph for the reader to understand. The topic sentence is usually the first sentence of a paragraph. It makes a statement (about a topic) and the rest of the paragraph explains the topic sentence or gives examples of the topic sentence. The second sentence of a paragraph can sometimes be the topic sentence. Sometimes it is called a summary sentence.
No, a supporting sentence supports the topic sentence.
if a paragraph does not have a topic sentence then
The sentence that states the main idea of the paragraph is called the 'Topic Sentence'.
Final.
A topic sentence is a sentence that explains your topic.
There are indeed three types of supporting details, namely, supporting sentences, detail sentences and concluding sentence. The supporting sentences is tied to the topic sentence; the detail sentences is related to supporting sentences, and concluding sentence re-emphasize the the topic sentence. In fact, there are four elements in a good paragraph - topic sentence, supporting sentences, detail sentences and concluding sentence. I hope that solves your problem.
A topic sentence grabs a readers attention
The sentences that restates the topic sentence.